Mr Martin McGuinness is to begin proceedings in the Belfast High Court tomorrow to overturn Mr David Trimble's bar on Sinn Fein ministers attending North-South Ministerial Council (NSMC) meetings.
Mr McGuinness, in his capacity as Minister of Education, wants the High Court to rule that he can officially meet his Dublin counterpart, Dr Michael Woods, at an NSMC meeting in Dublin on Friday.
Mr McGuinness is taking the action in an attempt to ensure the meeting has full NSMC status.
The Minister of Health, Ms Bairbre de Brun, has already embarked on a case against Mr Trimble's ruling that Sinn Fein ministers cannot attend NSMC meeting until the IRA re-engages with Gen John de Chastelain's decommissioning body.
The Sinn Fein chairman, Mr Mitchel McLaughlin, said this latest action was inevitable "because of David Trimble's strategy of fracturing the all-Ireland dimension of the Good Friday agreement.
"David Trimble has set the political process on a course for collapse. The political institutions are both interlocked and interdependent. His decision to fracture the all-Ireland aspect of the agreement has obvious knock-on effects for the other constitutional and institutional aspects of the agreement," Mr McLaughlin added.
He said the Northern Secretary, Mr Peter Mandelson, should intervene to ensure the NSMC meeting goes ahead on Friday.
"He has used this power in the past to cause negative effects on the process, particularly his decision to collapse the political institutions in February and his decision to force the flying of the Union Jack," Mr McLaughlin said.
